1. Field of the Invention
This invention relates in general to memories and more specifically to refreshing DRAM cells based on temperature.
2. Description of the Related Art
A dynamic random access memory (DRAM) is a type of memory technology which stores data in cells. Each DRAM cell typically includes a capacitive element for storing charge indicative of the logical value stored in the cell. The charge stored in the capacitive element may leak over time. Accordingly, the memory cells of an array need to be refreshed. In one example of a refresh operation, a determination is made of whether a cell is storing a logical value corresponding to a high charge to be stored on the capacitive element or whether the cell is storing a logical value corresponding to a low charge (or no charge) to be stored on the capacitive element. If a high charge is to be stored, the refresh circuitry restores the full charge to the capacitor of the cell.
Refresh operations however, require time to perform the refresh cycle which prevents data from being written to or read from the DRAM array. Also, refresh cycles consume power.
What is desired is an improved system for refreshing a DRAM.
The use of the same reference symbols in different drawings indicates identical items unless otherwise noted. The figures are not necessarily drawn to scale.